US Patent 8489612 Identifying similar files in an environment having multiple client computers

To identify similar files in an environment having multiple client computers, a first client computer receives, from a coordinator computer, a request to find files located at the first client computer that are similar to at least one comparison file, wherein the request has also been sent to other client computers by the coordinator computer to request that the other client computers also find files that are similar to the at least one comparison file. In response to the request, the first client computer compares signatures of the files located at the first client computer with a signature of the at least one comparison file to identify at least a subset of the files located at the first client computer that are similar to the at least one comparison file according to a comparison metric. The first client computer sends, to the coordinator computer, a response relating to the comparing.